It’s striking how predictable Oda’s writing is.
Imu isn’t putting up any resistance right now, so he’s bound to use some power, whether it’s a hybrid form or those polar eyes of his (which would justify the flashback), and put Luffy and Loki in a tight spot, maybe even turning it into a 2v2. But they’ll ultimately be defeated after Loki uses his hybrid form and Luffy pulls off some of that Nika plot things.